The Eleventh Gordon Conference on Molecular Pharmacology will focus on "Mechanisms of Transmembrane Signaling" and the "Molecular Bases of Drug Specificity," areas of rapid research advances in molecular pharmacology. The conference is designed to promote exchange of ideas and information among participants who investigate a broad range of problems related to these topics. Recent developments in recombinant DNA technology employing site specific mutagenesis and in computer graphics enable a meshing of these areas where the currents in molecular pharmacology and medicinal chemistry are now beginning to merge. The conference will emphasize these subjects to foster a broader appreciation of the respective fields. The invited speakers use a wide range of experimental approaches, ranging from physical-chemical analyses of structure to molecular genetics. The list includes scientists from universities, research institutes, and industrial laboratories. They have been chosen with special attention to attracting excellent young scientists, along with a group of established investigators in each subfield. We expect a large number of applicants for the conference; of these, approximately 120 will be chosen, according to three criteria: 1. broad representation of disciplines and institutions; 2. selection of women, young scientists, students and fellows; 3. likelihood of significant contributions to discussions and poster sessions. Investigators are discovering a remarkably conserved set of molecular mechanisms that underlie the extraordinary diversity of transmembrane signaling. The mechanisms include receptor-regulated G proteins and the related ras proteins, second messengers such as cAMP, Ca2+ and phosphoinositides, ligand- and voltage-gated channels, regulation of transcription, and receptors that initiate tyrosine phosphorylation and mediate the actions of insulin and other growth factors. These mechanisms form the basis of information processing and transfer in the central nervous system; of the initiation, conduction, and regulation of impulses in the heart; of the regulation of metabolism and proliferation of normal and malignant cells; and of the regulation of inflammation and immune responses. Accordingly, the topics to considered extend across the purviews of NIGMS, NINCDS, NHLBI, NIADDK, and NCI.